(Wikipedia) When Lindberg received Troorkh, he considered it to be "practically unplayable", with 56 high Fs and 2 F-sharps. However, he was ready to premiere it in 1993, in which he received a standing ovation. Subsequently, Xenakis sent him 28 red roses, half a rose each high F, and stated that, in his opinion, Lindberg was the best trombone player at that time. This composition is his last composition for a solo instrument and orchestra.[2]

(Wikipedia) When Lindberg received Troorkh, he considered it to be "practically unplayable", with 56 high Fs and 2 F-sharps. However, he was ready to premiere it in 1993, in which he received a standing ovation. Subsequently, Xenakis sent him 28 red roses, half a rose each high F, and stated that, in his opinion, Lindberg was the best trombone player at that time. This composition is his last composition for a solo instrument and orchestra.[2]